A number of programmable proximity switches have been previously proposed. Particularly, programming of a proximity switch, and then final trimming thereof has been proposed in the art, e.g. in: U.S. Pat. No. 5,408,132 (Sorin Fericern, et al); U.S. Pat. No. 4,713,602 (UEDA); and commercially available products from XICOR, INC of the USA which provide for remote trimming after construction. Also proposed has been an inductive proximity switch with a temperature dependent set point as in U.S. Pat. No. 5,119,004 (HOEDIMAYR et al). The content of the aforementioned prior art documents are incorporated herein by reference.
Known proximity switches suffer from a number of disadvantages, and the present invention obviates or at least mitigates one or more of these disadvantages.